Wireless local area network receiver and associated method

ABSTRACT

A wireless local area network (WLAN) includes a server and receiver, which includes a radio frequency (RF) front-end circuit that receives wireless signals from the mobile nodes within the WLAN and detects baseband signals. A signal waveform detector edge detects a signal waveform and generates a trigger signal indicative of the modulation type, data format and time-of-arrival (TOA) information of a desired signal to be captured. A baseband processor receives the trigger signal from the signal waveform detector and captures the desired signal. A system controller is connected to the baseband processor and configures the baseband processor for processing the desired signal and obtaining message data and signal metrics that are transferred to the system controller to be communicated outbound from the receiver as a client to the server.

RELATED APPLICATION

This application is based upon prior filed copending provisionalapplication Ser. No. 60/787,885 filed Mar. 31, 2006.

FIELD OF THE INVENTION

This invention relates to the field of wireless local area networks(WLAN's), and more particularly, this invention relates to real-timelocation systems and WLAN's.

BACKGROUND OF THE INVENTION

Wireless local area networks (WLAN) and real-time location systems(RTLS) are becoming more commonplace as the use of portable computers,such as “laptop,” “notebook,” and “pen” computers become increasinglycommon in office environments and other locations. Examples of real-timelocation systems and the circuitry and algorithms used in such real-timelocation systems are described in commonly assigned U.S. Pat. Nos.5,920,287; 5,995,046; 6,121,926; and 6,127,976, the disclosures whichare hereby incorporated by reference in their entirety. Examples ofreal-time location systems that are operative with wireless local areanetworks are disclosed in commonly assigned U.S. Pat. Nos. 6,892,054;6,987,744; 7,046,657; and 7,190,271, the disclosures which are herebyincorporated by reference in their entirety.

It is desirable in some WLAN systems if a real-time location system canincorporate a receiver that connects to a network as a client, which issimple, and incorporates existing information technology (IT)communications systems, and could be used in conjunction with an accesspoint or alone, and provide some ability to locate access points andcommunicate to a server.

SUMMARY OF THE INVENTION

A wireless local area network (WLAN) includes a server and receiver incommunication with the server as a network client. The receiver includesa radio frequency (RF) front-end circuit that receives wireless signalsfrom the mobile nodes within the WLAN and detects baseband signals. Asignal waveform detector is connected to the RF front-end circuit foredge detecting a signal waveform and generating a trigger signalindicative of the modulation type, data format and time-of-arrival (TOA)information of a desired signal to be captured. A baseband processor isconnected to the RE front-end circuit and the signal waveform detectorand receives the trigger signal from the signal waveform detector andcaptures the desired signal. A system controller is connected to thebaseband processor and configures the baseband processor for processingthe desired signal and obtaining message data and signal metrics thatare transferred to the system controller to be communicated outboundfrom the receiver to the server.

A media access control (MAC) device is connected between the systemcontroller and server. A TOA processor is connected to the basebandprocessor and receives the TOA information and generates the time stampfor the desired signal. In this non-limiting example, the TOA processorcan be operative for processing TOA information when the receiver ispart of a geometric array of network nodes and determine first-to-arrivesignals based on a common network timing signal and conductdifferentiation of the first-to-arrive signals to locate a desiredwireless node.

In yet another aspect, a wireless network connection exists between theserver and the receiver. In still another aspect, a wired networkconnection exists between the server and the receiver.

It is possible to have diversity antennas connected to the RF front-endcircuit and provide spatial diversity. The system controller can beoperative for controlling RF signal selection to dual RF channelsconnected to the diversity antennas. A wireless access point isconnected to the receiver. A multiplexer switch can be connected betweenthe receiver and the wireless access point for selectively switchingbetween the receiver and the wireless access point.

A method aspect is also set forth.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention willbecome apparent from the detailed description of the invention whichfollows, when considered in light of the accompanying drawings in which:

FIG. 1 is a block diagram of a WLAN system showing basic components of aWLAN receiver in accordance with a non-limiting example of the presentinvention.

FIG. 2 is a block diagram of an example of a diversity antenna for thereceiver in accordance with a non-limiting example of the presentinvention.

FIG. 3 is a block diagram of an active antenna for the receiver inaccordance with another non-limiting example of the present invention.

FIG. 4 is a high-level block diagram of one example of the circuitarchitecture that can be modified for use as part of a processor fordetermining first-to-arrive signals.

FIG. 5 is another high-level block diagram of an example of the circuitarchitecture that can be used as modified for correlation-based signalprocessors.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout, and prime notation is used toindicate similar elements in alternative embodiments.

In accordance with a non-limiting example of the present invention, aWLAN system includes a receiver that is connected to a network as aclient. It is usable as a “soft” (modular and software upgradable)location processor system for different types of wireless signal formatsand frequencies or combinations. It could be operative as a system forlocating WLAN terminals and tag transmitter location, for example,operative with Wherenet ISO24730 devices.

Low complexity and simplicity of operation with existing informationtechnology communications networks is provided. The receiver can beoperative as an active antenna and can isolate the real-time locationsystem (RTLS) layer from the network and allow upgrades for moreflexibility. It can comply with existing and evolving network securityprocesses by having the receiver operate as a client and not as anaccess point (AP). The receiver can lower the cost of a real-timelocation system detection in a physical layer. The receiver can beremotely set to modulation formats and frequencies that are completelyindependent of a host access point.

A receiver for use in the illustrated WLAN system, in accordance with anon-limiting example of the present invention, is shown in FIG. 1 at 10.The RF antenna 12 can be a single frequency or multi-band antenna.Various other wireless nodes are illustrated as part of the WLAN. Aconfigurable RF front-end circuit 14 can also be single frequency ormulti-band for receiving multiple frequencies. The RF front-end circuit14 is configured for baseband detection 16, which can be either a fullor partial bandwidth to constrain the number of detected signals.

A configurable signal waveform detector 18 can be remotely set forinitial edge detection of a desired signal waveform (or waveforms) to beprocessed. A trigger signal is generated at 20 to a baseband processor22 for the desired signal and modulation type, data format andtime-of-arrival (TOA) capture configurations. This trigger signal isgenerated for each desired signal to be captured. The baseband processor22 is operative at a real-time configuration and detects the desiredsignal waveform and data. This baseband processor 22 can supportmultiple waveform types and the signal capture can be a priori totrigger generation. The waveform capture occurs in real-time during thetrigger signal generation.

As illustrated, the detected signal waveform capture can either be sentto the system controller 26 for communication to a remotetime-of-arrival (TOA) processor, or an on-board TOA processor 28 canproduce a time stamp for arrival of the captured signal. Thetime-of-arrival information can be sent to the system controller 26. Themessage data and signal metrics can be sent to the system controller 26,which can manage both the real-time configuration of the receiver 10 andthe data to be communicated outbound through the media access controller(MAC) device 34 to a server 36. The illustrated receiver 10 wouldinclude its own MAC address.

At the RF front-end 14, the signal waveform detector 18 and basebandprocessor 22 can be real-time preconfigured by the system controller,based on locally generated and remote system requirement-basedinstructions. The MAC device 34 directs data, as a client, througheither a wired or wireless connection, to the host network.

It should be understood that the configurable signal waveform detector18 can be formed as a number of detectors that are used for detecting anumber of desired signal waveforms. The system controller can alsofeedback specific signal mode and location asset identifier (ID)commands to the baseband processor that works in conjunction with theTOA processor 28 for determining asset locations such as a wireless node11.

FIG. 2 shows two antennas 50,52 operative with the receiver 10, whichcould include a dual channel processor indicated at 54. Antenna specialdiversity is provided. The processor 54 can be incorporated into the REfront-end circuit 14 or part of the baseband processor 22. The twoantennas 50,52 can be spaced apart to provide spatial diversity. Theprocessor 54 can be configured with a common signal processor and REsignal strength based selection of two RF front-end channels. It is alsopossible to configure two completely separated detection channels thatare controlled by the system controller.

As shown in FIG. 3, an active antenna system for a WLAN access point isillustrated. Two antennas 60,62 are illustrated and connected to a radiofrequency multiplexer 64 operative as a switch that connects into thedual channel processor 54, which could be similar to the processor shownin FIG. 2, and a WLAN access point 66. The REF multiplex switch (MUX) 64simultaneously receives RF signals for transmission to the receiver 10and host WLAN access point 66 as selected. The switch 64 selects betweenthe two “client” for RF transmission. This active antenna device canconnect to the access point 66 as a replacement for its normal passiveantenna and interfaces to a host access point as a wireless client. Thecircuit can include a preamplifier or RF line amplifier or othercomponent for an active antenna circuit.

There are various advantages of the receiver 10 as described. Theseadvantages include connectivity to an information communications networkas a client of that network, either wireless or wired. The receiver 10can be combined with an antenna as a location processor such asdescribed in the incorporated by reference patents and connect as anetwork client. It is also possible to use the device either as areplacement for an external antenna of a wireless network access point(AP) or as an independently located client.

It is also possible to direct remotely the receiver as an element of ageometric array for locating an asset such as an RF tag or wirelessnetwork client. It is also possible to reconfigure remotely in real-timethe receiver for a center RF receive frequency and RF and informationbandwidth. The receiver 10 can detect a desired signal format and selecta desired signal for detection and processing based on specific data inthe detected signal packet and/or data format such as a client ID, assetcategory, packet length and similar details. The receiver can beoperative as a system engine capable of detecting multiple modificationformats and RF frequencies in the order of incoming reception andaccording to a remote preset, such as the priority of signal type andthe frequency and the priority of signal ID.

For purposes of description, the type of location circuits, algorithm,and associated functions that can be modified for use with the presentinvention are set forth in the incorporated by reference patents. Forpurposes of description, FIGS. 4 and 5 describe representative examplesof circuit architectures that can be modified for use, in accordancewith non-limiting examples of the present invention, and used in thereceiver 10 architecture associated therewith.

FIG. 4 diagrammatically illustrates one type of circuitry configurationof a respective location receiver (or “reader”) architecture for“reading” location pulses or associated signals, “blink” as sometimesreferred, such as emitted from a mobile station. An antenna 210 sensesappended transmission bursts or other signals from a respective mobilestation. The antenna, which could be omnidirectional and circularlypolarized, is coupled to a power amplifier 212, whose output is filteredby a bandpass filter 214. Respective I and Q channels of the bandpassfiltered signal are processed in associated circuits corresponding tothat coupled downstream of filter 214. To simplify the drawing, only asingle channel is shown.

A respective bandpass filtered I/Q channel is applied to a first input221 of a down-converting mixer 223. Mixer 223 has a second input 225coupled to receive the output of a phase-locked local IF oscillator 227.IF oscillator 227 is driven by a highly stable reference frequencysignal (e.g., 175 MHz) coupled over a (75 ohm) communications cable 231from a control processor. The reference frequency applied tophase-locked oscillator 227 is coupled through an LC filter 233 andlimited via limiter 235.

The IF output of mixer 223, which may be on the order of 70 MHz, iscoupled to a controlled equalizer 236, the output which is appliedthrough a controlled current amplifier 237 and applied to communicationscable 231 to a communications signal processor, which could be anassociated processor 32,32 a. The communications cable 231 also suppliesDC power for the various components of the location receiver by way ofan RE choke 241 to a voltage regulator 242, which supplies the requisiteDC voltage for powering an oscillator, power amplifier and analogto-digital units of the receiver.

The amplitude of the (175 MHZ) reference frequency supplied by thecommunications control processor to the phase locked local oscillator227 implies the length of any communications cable 231 (if used) betweenthe processor and the receiver. This magnitude information can be usedas control inputs to an equalizer 236 and current amplifier 237, so asto set gain and/or a desired value of equalization, which may berequired to accommodate any length of a communication cable. For thispurpose, the magnitude of the reference frequency may be detected by asimple diode detector 245 and applied to respective inputs of a set ofgain and equalization comparators shown at 247. The outputs ofcomparators are quantized to set the gain and/or equalizationparameters.

FIG. 5 illustrates the architecture of a correlation-based, RF signalprocessor as part of processor to which the output of a respective RE/IFconversion circuit of FIG. 4 can be coupled for processing the outputand determining location. The correlation-based RF signal processorcorrelates spread spectrum signals detected by its associated receiverwith successively delayed or offset in time (by a fraction of a chip)spread spectrum reference signal patterns, and determines which spreadspectrum signal received by the receiver is the first-to-arrivecorresponding to a “blink” or location pulse as part of thecommunications signal that has traveled over the closest observable pathbetween a mobile station and a location receiver.

Because each receiver can be expected to receive multiple signals fromthe mobile station, due to multipath effects caused by the signaltransmitted by the mobile station being reflected off variousobjects/surfaces between the mobile station and the receiver, thecorrelation scheme ensures identification of the first observabletransmission, which is the only signal containing valid timinginformation from which a true determination can be made of the distancefrom the tag to the receiver.

For this purpose, as shown in FIG. 5, the RF processor employs afront-end, multi-channel digitizer 300, such as a quadrature IF-basebanddown-converter for each of an N number of receivers. The quadraturebaseband signals are digitized by associated analog-to-digitalconverters (ADCs) 272I and 272Q. Digitizing (sampling) the outputs atbaseband serves to minimize the sampling rate required for an individualchannel, while also allowing a matched filter section 305, to which therespective channels (reader outputs) of the digitizer 300 are coupled tobe implemented as a single, dedicated functionality ASIC, that isreadily cascadable with other identical components to maximizeperformance and minimize cost.

This provides an advantage over bandpass filtering schemes, whichrequire either higher sampling rates or more expensive ADCs that arecapable of directly sampling very high IF frequencies and largebandwidths. Implementing a bandpass filtering approach typicallyrequires a second ASIC to provide an interface between the ADCs and thecorrelators. In addition, baseband sampling requires only half thesampling rate per channel of bandpass filtering schemes.

The matched filter section 305 may contain a plurality of matched filterbanks 307, each of which is comprised of a set of parallel correlators,such as described in the above identified, incorporated by reference'926 patent. A PN spreading code generator could produce a PN spreadingcode (identical to that produced by the PN spreading sequence generatorof the location transmitter). The PN spreading code produced by a PNcode generator is supplied to a first correlator unit and a series ofdelay units, outputs of which are coupled to respective ones of theremaining correlators. Each delay unit provides a delay equivalent toone-half a chip. Further details of the parallel correlation aredisclosed in the '926 patent.

As a non-limiting example, the matched filter correlators may be sizedand clocked to provide on the order of 4×10⁶ correlations per epoch. Bycontinuously correlating all possible phases of the PN spreading codewith an incoming signal, the correlation processing architectureeffectively functions as a matched filter, continuously looking for amatch between the reference spreading code sequence and the contents ofthe incoming signal. Each correlation output port 328 is compared with aprescribed threshold that is adaptively established by a set of‘on-demand’ or ‘as needed’ digital processing units 340-1, 340-2, . . ., 340-K. One of the correlator outputs 328 has a summation valueexceeding the threshold, which delayed version of the PN spreadingsequence is effectively aligned (to within half a chip time) with theincoming signal.

This signal is applied to a switching matrix 330, which is operative tocouple a ‘snapshot’ of the data on the selected channel to a selecteddigital signal processing unit 340-i of the set of digital signalprocessing units 340. The mobile station can ‘blink’ or transmitlocation pulses randomly, and can be statistically quantified, and thus,the number of potential simultaneous signals over a processor revisittime could determine the number of such ‘on-demand’ digital signalprocessors required. A processor would scan the raw data supplied to thematched filter and the initial time tag. The raw data is scanned atfractions of a chip rate using a separate matched filter as aco-processor to produce an auto-correlation in both the forward (intime) and backwards (in time) directions around the initial detectionoutput for both the earliest (first observable path) detection and otherburied signals. The output of the digital processor is the first pathdetection time, threshold information, and the amount of energy in thesignal produced at each receiver's input, which is supplied to andprocessed by the time-of-arrival-based multi-lateration processorsection 400.

As a non-limiting example, the processor section 400 can use a standardmulti-lateration algorithm that relies upon time-of-arrival inputs fromat least three detectors to compute the location of the object. Thealgorithm may be one which uses a weighted average of the receivedsignals. In addition to using the first observable signals to determineobject location, the processor also can read any data read out of amobile station's memory and superimposed on the transmission. Objectposition and parameter data can be downloaded to a database where objectinformation is maintained. Any data stored in a mobile station memorymay be augmented by altimetry data supplied from a relativelyinexpensive, commercially available altimeter circuit. Further detailsof such circuit are disclosed in the '926 patent.

It is also possible to use an enhanced circuit as disclosed in the '926patent to reduce multipath effects, by using dual antenna and providingspatial diversity-based mitigation of multipath signals. In suchsystems, the antennas of each location receiver are spaced apart fromone another by a distance that is sufficient to minimize destructivemultipath interference at both antennas simultaneously, and also ensurethat the antennas are close enough to one another so as to notsignificantly affect the calculation of the location of the object bythe downstream multi-lateration processor.

The multi-lateration algorithm executed by the processor is modified toinclude a front-end subroutine that selects the earlier-to-arriveoutputs of each of the detector pairs as the value to be employed in themulti-lateration algorithm. A plurality of auxiliary ‘phased array’signal processing paths can be coupled to the antenna set (e.g., pair),in addition to the paths containing the directly connected receivers andtheir associated first arrival detector units that feed thetriangulation processor. Each respective auxiliary phased array path isconfigured to sum the energy received from the two antennas in aprescribed phase relationship, with the energy sum being coupled toassociated units that feed a processor as a triangulation processor.

The purpose of a phased array modification is to address the situationin a multipath environment where a relatively Tearlyl signal may becanceled by an equal and opposite signal arriving from a differentdirection. It is also possible to take advantage of an array factor of aplurality of antennas to provide a reasonable probability of effectivelyignoring the destructively interfering energy. A phased array provideseach site with the ability to differentiate between received signals, byusing the 1 pattern’ or spatial distribution of gain to receive oneincoming signal and ignore the other.

The multi-lateration algorithm executed by the processor could include afront-end subroutine that selects the earliest-to-arrive output of itsinput signal processing paths and those from each of the signalprocessing paths as the value to be employed in the multi-laterationalgorithm (for that receiver site). The number of elements and paths,and the gain and the phase shift values (weighting coefficients) mayvary depending upon the application.

It is also possible to partition and distribute the processing load byusing a distributed data processing architecture as described in theincorporated by reference U.S. Pat. No. 6,127,976. This architecture canbe configured to distribute the workload over a plurality ofinterconnected information handling and processing subsystems.Distributing the processing load enables fault tolerance through dynamicreallocation.

The front-end processing subsystem can be partitioned into a pluralityof detection processors, so that data processing operations aredistributed among sets of detection processors. The partitioneddetection processors can be coupled in turn through distributedassociation processors to multiple location processors. For maximummobile station detection capability, each receiver is preferablyequipped with a low cost omnidirectional antenna that provideshemispherical coverage within the monitored environment.

A detection processor filters received energy to determine the earliesttime-of-arrival energy received for a transmission, and thereby minimizemulti-path effects on the eventually determined location of a mobiledevice. The detection processor can demodulate and time stamp allreceived energy that is correlated to known spreading codes of thetransmission, so as to associate a received location pulse with only onemobile station. It then assembles this information into a message packetand transmits the packet as a detection report over a communicationframework to one of the partitioned set of association processors, andthen de-allocates the detection report.

A detection processor to association control processor flow controlmechanism can equitably distribute the computational load among theavailable association processors, while assuring that all receptions ofa single location pulse transmission, whether they come from one ormultiple detection processors, are directed to the same associationprocessor.

The flow control mechanism can use an information and processing loaddistribution algorithm, to determine which of the association processorsis to receive the message, and queues the message on a prescribedprotocol coupling socket connecting the detection processor to thedestination association processor. To select a destination associationprocessor, the information and processing load distribution algorithmmay include a prime number-based hashing operation to ensure a veryuniform distribution of packets among association processors. Inaddition, to provide relatively even partitioning in the case of widelyvarying transmission rates, the hashing algorithm may use a sequencenumber contained in each transmission.

Each association processor can organize its received message packets byidentification (ID) and time-of-arrival (TOA), and stores them asassociation reports. The association processor compresses the datawithin the association report, transmits that information over anassociation communication process of the communication framework to oneof a plurality of distributed location processors, and then de-allocatesthe association report.

In order to deliver all association reports that have been generated foran individual mobile station (or device) to a single destinationlocation processor, the association communication process of thecommunication framework may employ the same information and processingload distribution algorithm executed by the detection communicationprocess of the communication framework. Each location processordetermines the geographical location of a mobile station using thetime-of-arrival measurement information originally sourced from thedetection processors. The specific algorithm employed for locationdetermination matches the number of arrival time measurements withwhatever a priori information is available.

To locate a mobile station, a location processor may employ allavailable diversity information associated with the mobile station ofinterest, including, but not limited to the mobile station ID, any datacontained in the transmission and metrics indicating confidence in thesevalues. It then forwards a location report containing this informationover a location communication process to an asset management database. Alocation estimate may be derived from the measured time-of-arrivalinformation in a received association report packet, using adifferential time-of-arrival algorithm, such as a hyperbolicgeometry-based function.

It is also possible to use a wireless local area network (WLAN) spreadspectrum waveform to perform the geo-location function of the presentinvention. The assumption is that the wireless communications signal, asa spread spectrum signal, has a high signal-to-noise ratio withreasonable power levels. The leading edge of this communication signalcan be detected to a high accuracy and this information used with thealgorithms as described before to provide relative time of arrivalinformation for subsequent processing. It is also possible to have atiming signal from a known location. Other component locations wouldhave to be known, of course. For example, some wireless local areanetwork (WLAN) transmitters have known locations to enable the use ofthe algorithm when an access point base station or mobile stationlocation is known.

It is also known that the communications signal as a spread spectrumcommunications signal can have sufficient bandwidth to provide usefultime accuracy. For example, a 50 MHz bandwidth could provideapproximately 5 nanoseconds of timing accuracy that is about 5 feet ofaccuracy using much of the technology and teachings described before. Itis possible to use a correlator operative as a functional spreadspectrum matched filter to enable a higher quality estimate withintegration over many chips of the spread spectrum transmission. It ispossible to use a matched filter that spans multiple symbols and improveaccuracy by collecting more energy in the filter prior to leading edgedetection.

Many modifications and other embodiments of the invention will come tothe mind of one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is understood that the invention is not to be limited tothe specific embodiments disclosed, and that modifications andembodiments are intended to be included within the scope of the appendedclaims.

1. A wireless local area network (WLAN), comprising: a server; areceiver in communication with said server as a network client, andcomprising, a radio frequency (RE) front-end circuit that receiveswireless signals from mobile nodes within the WLAN and detects basebandsignals; a signal waveform detector connected to the RF front-endcircuit for edge detecting a signal waveform and generating a triggersignal indicative of the modulation type, data format andtime-of-arrival (TOA) information of a desired signal to be captured; abaseband processor connected to the RF front-end circuit and the signalwaveform detector that receives the trigger signal from the signalwaveform detector and captures the desired signal; and a systemcontroller connected to the baseband processor that configures thebaseband processor for processing the desired signal and obtainingmessage data and signal metrics that are transferred to the systemcontroller to be communicated outbound from the receiver to the server.2. The WLAN according to claim 1, and further comprising a media accesscontrol (MAC) device connected between said system controller and saidserver.
 3. The WLAN according to claim 1, and further comprising a TOAprocessor connected to said baseband processor that receives the TOAinformation and generates a time stamp for the desired signal.
 4. TheWLAN according to claim 3, wherein said TOA processor is operative forprocessing TOA information when said receiver is part of a geometricarray of networked nodes and determining first-to-arrive signals basedon a common network timing signal and conducting differentiation of thefirst-to-arrive signals to locate a desired wireless node.
 5. The WLANaccording to claim 1, and further comprising a wireless networkconnection between said server and said receiver.
 6. The WLAN accordingto claim 1, and further comprising a wired network connection betweensaid server and said receiver.
 7. The WLAN according to claim 1, andfurther comprising diversity antennas connected to the RF front-endcircuit and providing spatial diversity.
 8. The WLAN according to claim7, wherein said system controller is operative for controlling signalselection and RF signal based selection of dual RF channels connected tosaid diversity antenna.
 9. The WLAN according to claim 1, and furthercomprising a wireless access point connected to said receiver.
 10. TheWLAN according to claim 9, and further comprising a multiplexer switchconnected between said receiver and said wireless access point forselectively switching signals between said receiver and said wirelessaccess point.
 11. A receiver operative as a client in a wireless localarea network (WLAN) r comprising: a radio frequency (RE) front-endcircuit that receives wireless signals from mobile nodes within the WLANand detects baseband signals; a signal waveform detector connected tothe RE front-end circuit for edge detecting a signal waveform andgenerating a trigger signal indicative of the modulation type, dataformat and time-of-arrival (TOA) information of a desired signal to becaptured; a baseband processor connected to the RF front-end circuit andthe signal waveform detector that receives the trigger signal from thesignal waveform detector and captures the desired signal; and a systemcontroller connected to the baseband processor that configures thebaseband processor for processing the desired signal and obtainingmessage data and signal metrics that are transferred to the systemcontroller to be communicated outbound from the receiver to the server.12. The receiver according to claim 11, and further comprising a mediaaccess control (MAC) device connected between said system controller andsaid server.
 13. The receiver according to claim 11, and furthercomprising a TOA processor connected to said baseband processor thatreceives the TOA information and generates a time stamp for the desiredsignal.
 14. The receiver according to claim 11, wherein said TOAprocessor is operative for processing TOA information when said receiveris part of a geometric array of networked nodes and determiningfirst-to-arrive signals based on a common network timing signal andconducting differentiation of the first-to-arrive signals to locate adesired wireless node.
 15. The receiver according to claim 11, andfurther comprising a wireless network connection between said server andsaid receiver.
 16. The receiver according to claim 11, and furthercomprising a wired network connection between said server and saidreceiver.
 17. The receiver according to claim 11, and further comprisingdiversity antennas connected to the RF front-end circuit and providingspatial diversity.
 18. The receiver according to claim 17, wherein saidsystem controller is operative for controlling signal selection and RFsignal based selection of dual REF channels.
 19. The receiver accordingto claim 11, and further comprising a wireless access point connected tosaid receiver.
 20. The receiver according to claim 19, and furthercomprising a multiplexer switch connected between said receiver and saidwireless access point for selectively switching signals between saidreceiver and wireless access point.
 21. A method of communicating withina wireless local area network (WLAN), comprising, receiving at areceiver wireless signals transmitted from mobile nodes within the WLAN;detecting baseband signals within the receiver; generating a triggersignal indicative of a modulation type, data format and time-of-arrival(TOA) information of a desired signal to be captured; receiving thetrigger signal and in response, capturing the desired signal; processingthe desired signal to obtain message data and signal metrics; andtransmitting the message data and signal metrics to a WLAN server. 22.The method according to claim 21, which further comprises transmittingthe message data and signal metrics through a media access control (MAC)device connected between the receiver and a WLAN server.
 23. The methodaccording to claim 21, which further comprises receiving TOA informationand generating a time stamp for the desired signal.
 24. The methodaccording to claim 23, which further comprises processing TOAinformation and determining a first-to-arrive signal based on a commontiming signal and conducting differentiation of the first-to-arrivesignals to locate a desired wireless node.
 25. The method according toclaim 21, which further comprises controlling signal selection into dualRF channels based on RE signal detection.
 26. The method according toclaim 21, which further comprises transmitting the message data andsignal metrics through a wireless access point operative with thereceiver.